Originally Posted by Mike@N54Tuning.com
With a piggy like the JB4 the ECU never sees values other then stock like. As for removing. Clear the codes if any from the steering wheel, turn off power, lock the doors and remove the JB4.
Enjoy a much slower driver to the dealer
ive been gettin hpfp codes but only under heavy boost when the car is shifting gears in 1st,2nd, sometimes 3rd... car is going to the dealer on wed for the hpfp warranty and the battery cable recall...im not sure if i take the jb4 out if i can replicate the fuel pump misfires while stock...if i just remove the jb4 and leave the codes do u think bmw will find out? my only codes are the exhaust flap, radiator bind, and the fuel pump code